1. Field of the Invention
The present invention is directed to a lawn mower, and more particularly, to a lawn mower in which the rear wheel mounting structure is pivotally connected to the lawn mower frame and in which a lever engaging apparatus is provided for raising and lowering the frame with respect to the wheels. Further, the invention is directed to a lawn mower which enables the independent control of the drive wheels along with a safety mechanism.
2. Description of the Prior Art
In prior art lawn mowers, the wheel mounting structure is bolted to the lawn mower frame, and in order to raise or lower the frame to thereby raise or lower the mower's cutting deck, it is necessary to remove the bolts and raise the frame with respect to the wheels and then re-bolt the frame to the wheel mounting structure. This arrangement makes it difficult to raise and lower the cutting height of the lawn mower, particularly when this structure is used on large commercial-type lawn mowers.
Another problem which occurs in commercial-type lawn mowers having a plurality of cutting blades, is that the front wheels push down the grass and then the cutting blade, as it rotates from front to rear, passes over the top of the bent grass and does not cut it. This results in the uneven cutting of the grass, leaving the grass longer in the areas that the wheels have travelled over.
In prior art commercial lawn mowers in which the rear drive wheels are independently driven by hydraulic pumps associated with each rear wheel, the operation of the hydraulic pumps and thus the drive wheels is controlled by hand controls located on the hand grips of the lawn mower. A linkage extends from the hand grips to the hydraulic pump structure. In the prior art mowers, the linkages are located towards the outer sides of the mowers and are exposed, and thus, are subject to be hit by bushes, shrubs and other structures which the lawn mower may come in contact with during a cutting operation.